(a) This subpart, except §§ 113.25-25 and 113.25-30, applies to each manned vessel of over 100 gross tons, except barges, scows, and similar vessels.

(b) Section 113.25-25 applies to each manned ocean and coastwise barge of over 100 gross tons if the crew is divided into watches for the purpose of steering.

(c) Section 113.25-30 applies to each barge of 300 or more gross tons that has sleeping accommodations for more than six persons.

Each vessel must have a general emergency alarm system that meets the requirements of this subpart.

(a) Passenger vessels and cargo and miscellaneous vessels. Each passenger vessel, cargo vessel, and miscellaneous vessel must have a manually operated contact maker for the general emergency alarm system:

(1) In the navigating bridge; and

(2) At the feeder distribution panel if the general alarm power supply is not in or next to the navigating bridge.

(b) Tank vessels. Each tank vessel must have a manually operated contact maker for the general emergency alarm system:

(1) In the navigating bridge;

(2) At the deck officers' quarters farthest from the engineroom;

(3) in the engineroom;

(4) At the location of the emergency means of stopping cargo transfer required under 33 CFR 155.780; and

(5) At the feeder distribution panel if the general alarm power supply is not in or next to the navigating bridge.

(c) Mobile offshore drilling units. Each mobile offshore drilling unit must have a manually operated contact maker for the general emergency alarm system:

(1) In the main control room;

(2) At the drilling console;

(3) At the feeder distribution panel;

(4) In the navigating bridge, if a navigating bridge is installed; and

(5) In a routinely occupied space that is as far as practicable from all other contact makers.

(d) Additional contact maker. A vessel must not have more than one other contact maker that operates the general emergency alarm system in addition to those required under paragraph (a), (b), or (c) of this section unless the installation of other contact makers has been accepted by the Commandant.

(e) Special system. If a vessel has an emergency squad when operating, has a manual fire alarm system, or is an ocean-going passenger vessel, it must have:

(1) An independent manually operated contact maker in the navigating bridge that is connected to operate only the general emergency alarm signal in crew's quarters and machinery spaces; or

(2) A separate alarm system that sounds in the crew's quarters and machinery spaces.

The emergency power source for the general emergency alarm system must meet the requirements of IMO SOLAS 74 (incorporated by reference; see 46 CFR 110.10-1), Regulation II-1/42 or II-1/43, as applicable.

(a) If the general emergency alarm system is the only load supplied by the general emergency alarm system battery or batteries, the battery or batteries must have an enclosed fused switch or circuit breaker that has a means of locking. The fused switched or circuit breaker must be outside of, and next to, the battery room or battery locker, and the capacity of the fuses or circuit breaker must be at least 200 percent of the connected load.

(b) If the general emergency alarm system is supplied from an emergency or interior communication switchboard, or if duplicate general alarm batteries supply other loads, there must be a fused switch or circuit breaker supplying the general emergency alarm system that has a means of locking.

(a) Each system must have a feeder distribution panel to divide the system into the necessary number of zone, feeders, except where, because of the arrangement of the vessel, only one zone feeder is necessary; then a branch circuit distribution panel or feeder distribution panel must be used.

(b) The feeder distribution panel must have overcurrent protection for each zone feeder, but there must be no disconnect switches.

(c) The feeder distribution panel must be in an enclosed space next to the general alarm power supply.

(d) Each system must have at least one feeder for each vertical fire zone that has general emergency alarm signal.

(e) Each system must have one or more branch circuit distribution panels for each zone feeder, with at least one fused branch circuit for each deck level. The distribution panel must be above the uppermost continuous deck, in the zone served, and there must be no disconnect switches for the branch circuits.

(f) A branch circuit must not supply emergency alarm signal on more than one deck level, except for a single branch circuit supplying all levels of a single space containing more than one deck level if all other requirements of this section are met.

(g) On a vessel not divided into fire zones by main vertical fire bulkheads, the general emergency alarm system must be arranged into vertical service zones not more than 40 meters (131 feet) long, and there must be a general alarm feeder for each of these zones that has general emergency alarm signal.

(h) General alarm feeders and branch circuit cables must be in passageways and must not be in staterooms, lockers, galleys, machinery spaces, or other enclosed spaces, unless it is necessary to supply general emergency alarm signal in those spaces.

General emergency alarm signal must:

(a) Be located in passenger and crew quarters areas where they can alert persons in spaces where those persons may be maintaining, repairing, or operating equipment, stowing or drawing stores or equipment, or transiting, such as public spaces, work spaces, machinery spaces, workshops, galleys, emergency firepump room, bow thruster rooms, storage areas for paint, rope, and other stores, underdeck passageways in cargo areas, steering gear rooms, windlass rooms, holds of roll-on/roll-off vessels, and, except those that are accessible only through bolted manhole covers, duct keels with valve operators; and

(b) Be audible in the spaces identified in paragraph (a) of this section with all normally closed doors and accesses closed; and

(c) Be installed in cabins without loudspeaker installation. Other audible devices, such as electronic alarm transducers, are permitted.

(a) In a space described in § 113.25-9(a), where the general emergency alarm signal cannot be heard over the background noise, there must be a red-flashing light or rotating beacon, in addition to the general emergency alarm signal, that:

(1) Has sufficient intensity above the background lighting that would alert personnel in the space;

(2) Is activated whenever the general emergency alarm signal in the space are activated; and

(3) Is supplied by the general emergency alarm system power supply or the vessel emergency power source through a relay that is operated by the general emergency alarm system.

(b) A red-flashing light or rotating beacon must be installed so that it is visible in the cargo pump rooms of vessels that carry combustible liquid cargoes. The installation must be in accordance with the requirements of part 111, subpart 111.105, of this chapter.

Each contact maker must—

(a) Have normally open contacts and be constructed in accordance with Type 4 or 4X of NEMA 250 or IP 56 of IEC 60529:2013 (both incorporated by reference; see § 110.10-1 of this subpart) requirements;

(b) Have a switch handle that can be maintained in the “on” position;

(c) Have the “off” and “on” positions of the operating handle permanently marked; and

(d) Have an inductive load rating not less than the connected load or, on large vessels, have auxiliary devices to interrupt the load current.

(a) Each general emergency alarm signal must be an electrically-operated bell, klaxon, or other warning device capable of producing a signal or tone distinct from any other audible signal on the vessel.

(b) Electronic devices used to produce the general emergency alarm signal must meet the requirements of subpart 113.50 of this part.

(c)(1) The minimum sound-pressure levels for the emergency-alarm tone in interior and exterior spaces must be a sound level of not less than 80 dB(A) measured at 10 feet on the axis; and

(2) At least 10 dB(A) measured at 10 feet on the axis, above the background noise level when the vessel is underway in moderate weather unless flashing red lights are used in accordance with 46 CFR 113.25-10(b).

(d) Alarm signals intended for use in sleeping compartments may have a minimum sound level of 75 dB(A) measured 3 feet (1 meter) on axis, and at least 10 dB(A) measured 3 feet (1 meter) on axis, above ambient noise levels with the ship under way in moderate weather.

Each cable entrance to an emergency alarm signal or distribution fitting must be made watertight by a terminal or stuffing tube.

Each distribution panel must:

(a) Be watertight;

(b) Need a tool to be opened.

(a) Each fuse in a general emergency alarm system must meet the requirements of part 111, subpart 111.53, of this chapter.

(b) Each overcurrent protection device must cause as wide a differential as possible between the rating of the branch circuit overcurrent protection device and that of the feeder overcurrent protection device.

(c) The capacity of the feeder overcurrent device must be as near practicable to 200 percent of the load supplied. The capacity of a branch circuit overcurrent device must not be higher than 50 percent of the capacity of the feeder overcurrent device.

(a) Each general emergency alarm system fused switch and distribution panel must have a fixed nameplate on the outside of its cover that has a description of its function. The rating of fuses must also be shown on the outside of the cover of a fused switch.

(b) Each general alarm contact maker must be marked “GENERAL ALARM” in red letters on a corrosion-resistant plate or on a sign.

(c) A contact maker that operates only the general emergency alarm signal in crew quarters, machinery spaces, and work spaces must be marked “CREW ALARM” by the method described in paragraph (b) of this section.

(d) Each general emergency alarm signal must be marked “GENERAL ALARM—WHEN EMERGENCY ALARM SIGNAL RINGS GO TO YOUR STATION” in red letters at least 1/2 inch high.

(e) Each general emergency alarm system distribution panel must have a directory attached to the inside of its cover giving the designation of each circuit, the area supplied by each circuit, and the rating of each circuit fuse.

A manned ocean or coastwise barge of more than 100 gross tons, if it is one that operates with the crew divided into watches for steering the vessel, must have an emergency alarm signal installation. The system must:

(a) Have an automatically charged battery as the power source;

(b) Have a manually operated contact maker at the steering station and in the crew accommodation area; and

(c) Must meet the requirements of § 113.25.7 and §§ 113.25-9 through 113.25-20 of this subpart.

The general emergency alarm system for a barge of 300 or more gross tons with sleeping accommodations for more than six persons must meet the requirements of Subpart 113.25, except as follows:

(a) The number and location of contact makers must be determined by the design, service, and operation of the barge.

(b) If a distribution panel cannot be above the uppermost continuous deck because of the design of the barge and is installed below the deck, it must be as near the deck as practicable.